I see your use case. Since I consider this a very rare one, let me suggest another solution:
You could use a script, which enables all frames, resets all overrides and finally disables all frames again. You will need loopback and multiple external inputs per widget for this, which is currently only possible with the help of loopback (there was a thread about this, but I'm not able to find it at the moment). Please try it by yourself and ask if you are stuck. Unfortunately I don't have time at the moment to come up with a workspace file to illustrate what I mean.

After testing recent changes in slider monitor features I found a strange behavior. In the attached workspace I create 4 scenes this scenes controls dimmer fixtures.

Scene One with 2 dimmers first set to full, second set to zero.
Scene Two with 2 dimmers first set to zero, second set to full.
Scene One-1 with dimmer 1 set to full.
Scene Two-1 with dimmer 2 set to full.
Chaser OneTwo with scenes On and Two.
Chaser OneTwo-1 with scenes One-1 and Two-1

Virtual console
2 Sliders in monitor mode one per channel/dimmer.
Cue list OneTwo with scenes One and Two
Cue list OneTwo-1 with scenes One-1 and Two-1

Playing OneTwo cue list the sliders follow the values correctly, showing the values changing smoothly.
Playing OneTwo-1 cue list. When change to next step, the slider monitoring actual step falls to zero immediately, but the fixture monitor shows the correct values.

When there is a function running, you can adjust the slider by dragging the slider button with the mouse. The value of the channel changes (remains changed) and the red X becomes enabled and works as exected. But, you cannot use the mouse scroll button for this. For some reason, if you hover over the slider, and move the mouse scroller, then the value changes while you are scrolling, but it snaps back to the scene's value when you stop scrolling. It is as if the scroll button does not trigger the new code. If you first move the button with the mouse, then the scroll wheel works.

One of my main use cases for this, is to make small adjustments to moving head spotlight positions during a show, when the actor singer has not ended up where we programmed her/him to be. Being able to make small adjustments with the mouse would be perfect.

Really love the new slider / monitor functions. They work really well for me.

Just one question ...
When the the slider is in knob mode, is it supposed to have the monitor function as well?
I notice that the green monitor display follows the knob position, not the monitored level.
(qt4-git-4.10.6.20170310.2a70ac5-0 amd64)